Why can't I use a sexually explicit photo as an avatar?

Summary

We are strictly governed by Google and Apple in their T&C's that nothing which is sexually explicit, is allowed to be public facing - as youngsters obviously have access to Google Play and Apple iTunes and App Store. As such and due to the fact we have Apps with both, we cannot allow anything of a sexually explicit nature to be used as an avatar on the site. This is why upon joining if you use one, we will remove it or even as an established member and you change it to something explicit, it will be removed. We have no choice but to in this instance. Thank you for your understanding.